New Polymer Can Heal Itself Repeatedly

Scientists at UIUC, the University of Illinois at Urbana-Champaign, have recently developed a very unique polymer material that has the ability to heal itself over and over again when it cracks. The new polymer is designed to be like human skin. When human skin is cut, blood vessels from the inner layer deliver nutrients to the site of injury to aid healing. UIUC’s material acts in a similar way and consists of two layers. In order to test the material, the group of scientists bend it until the polymer coating cracks. Tests reveal that the material is capable of self-recovery up to seven times before being worn out.

“The polymer coating on top contains tiny catalyst pieces scattered throughout. The substrate contains a network of microchannels carrying a liquid healing agent. When the coating cracks, the cracks spread downward and reach the underlying channels, which ooze out healing agent. The agent mixes with the catalyst and forms a polymer, filling in the cracks.”

“The material's microchannel design could be a solution to the increasing problem of heat buildup in microelectronics chips. Typically, microelectronic circuit chips sit on substrates that are designed to conduct heat away from the circuit. These heat regulators have their limits.”

“You could put a cooling fluid through a [microchannel] network like a little mini-heat exchanger.”

It was about six years ago that UIUC announced the very first self-recovering material. Several other researchers have developed similar materials since then, but with different properties, including polymers that self-heal when subject to pressure or heat. Nonetheless, Nancy Sottos, an engineering professor who specializes in material science at UIUC and one of the leading researchers in the project, said that this new material presented by UIUC represents a new milestone, for it is the first synthetic material that is capable of repairing itself repeatedly without any external involvement.